Bi-doped antimony selenide (Sb 2−x Bi x Se 3 ) thin films have been prepared by potentiostatical electrodeposition and post annealing treatment. Cyclic voltammetry (CV) was used to investigate the electrochemical behaviors of electrodeposition. The suitable deposition potential for film preparation was determined to be about −0.40V vs. SCE combining with CV, energy dispersive X-ray spectroscopy (EDS), environmental scanning electron microscope (ESEM) studies. After annealing, film shows improved crystallinity and a basic orthorhombic Sb 2 Se 3 structure but having a larger d-spacing due to the substitution of Bi for Sb in Sb 2 Se 3 lattice. The annealed film exhibits an absorption coefficient of larger than 10 5 cm −1 in the visible region, an direct optical band gap of 1.12±0.01eV, the n-type conductivity, an carrier concentration of 1.1×10 19 cm −3 and an flat band potential of −0.40±0.03V vs. SCE.